In recent years, micro-analytical systems are used to carry out an analysis of trace substances such as proteins, nucleic acids (e.g., DNA) accurately and at high speed in the scientific field such as biochemistry and analytical chemistry or medical field.
An example of such micro-analytical systems is a system that performs electrophoresis using a micro-channel chip provided with a fine channel. After introducing a buffer solution and a sample into the channel of the micro-channel chip, this system performs electrophoresis on the sample. Reservoirs (concave) are formed at both ends of the channel, and the buffer solution and sample are introduced from these reservoirs into the channel. After introducing the buffer solution and sample, electrode rods are inserted into these two reservoirs and a voltage is applied to between the electrodes. Such a micro-channel chip is generally manufactured by bonding a film to a chip body in which a micro-groove (channel) and through holes (reservoirs) are formed.
As described above, in the conventional micro-channel chip, electrophoresis is performed with electrode rods being inserted in reservoirs. However, with the conventional micro-channel chip, when the electrode rod is inserted into the reservoir, there is a possibility that the buffer solution and sample may be contaminated. Furthermore, with the conventional micro-channel chip, the electrode rod needs to be inserted into the reservoir every time electrophoresis is performed. Thus, the conventional micro-channel chip involves problems of contamination and complexity of work.
In order to solve such problems, a micro-channel chip with an electrode layer arranged in a reservoir or channel is proposed (e.g., see Patent Literatures 1 and 2). For example, Patent Literature 1 discloses a micro-channel chip in which reservoirs are formed at both ends of the channel and electrode layers are arranged in these two reservoirs. These two electrode layers are connected to respective terminals outside the reservoirs. Therefore, electrophoresis can be performed by connecting external electrodes to these terminals without inserting the electrode rods into the reservoirs.    Patent Literature 1: U.S. Pat. No. 6,939,451    Patent Literature 2: Japanese Patent Application Laid-Open No. 2005-127771
According to the techniques described in Patent Literatures 1 and 2, a metal thin film or conductive ink layer is formed on a film bonded to a chip body to thereby form an electrode layer. After this, a micro-channel chip is manufactured by bonding the film on which the electrode layer is formed to the chip body.
FIG. 1A is a cross-sectional view for illustrating a conventional method of manufacturing a micro-channel chip including an electrode layer. As shown in FIG. 1A, the micro-channel chip is manufactured by bonding chip body 20 in which micro-groove 10 is formed to film 40 on which electrode layer 30 is formed by thermocompression.
However, using such a manufacturing method may produce gap 50 around electrode layer 30 due to the thickness of electrode layer 30 as shown in FIG. 1B. When gap 50 is produced around electrode layer 30, the liquid in the reservoir or channel may be leaked to the outside, posing a safety problem.
The chip body and film may be thermocompressed at a high temperature as means for preventing the occurrence of a gap. However, when thermocompression is performed at a high temperature, film 40 making up the bottom face of the channel may be deformed as shown in FIG. 1C. When film 40 is deformed in this way, the cross section of the channel changes and it is no longer possible to make an analysis with high accuracy.
Furthermore, the method of thermocompressing the chip body and film involves a problem that because the material of chip body 20 (e.g., resin) is different from the material of electrode layer 30 (e.g., carbon ink), the adherence between chip body 20 and electrode layer 30 is poor.
On the other hand, another means of bonding the chip body and film may be bonding using an adhesive. However, when an adhesive is used for bonding, adhesive 60 may stick out and the cross-sectional area of the channel may also change as shown in FIG. 1D.
As described so far, it is difficult for the prior arts to manufacture such a fluid handling apparatus (e.g., micro-channel chip) provided with a transfer function layer (e.g., electrode layer) that the size and shape of channels or reservoirs are accurately controlled and there is no gap around the transfer function layer.
It is an object of the present invention to provide a fluid handling apparatus provided with a transfer function layer for transferring electricity or heat, in which the size and shape of channels or reservoirs are accurately controlled and there is no gap around the transfer function layer. Furthermore, it is another object of the present invention to provide a fluid handling system including this fluid handling apparatus.